The invention relates generally to signal processing, and more particularly to a system and method for calibrating autoranging analog-to-signal conversion architecture.
Signal processing is a valuable tool for various applications that involve data transmission, data storage, and the like. One aspect of signal processing, for certain applications, is to convert an analog signal into its digital equivalent to facilitate storage, transmission, workability, signal conditioning, noise filtering, and the like.
One method for performing analog-to-digital (A/D) signal conversion is to use a single digital-to-analog converter (DAC) for providing a base analog signal for comparison to an input analog signal that requires conversion. To facilitate faster conversion rate in such a process, a segmented approach or an autoranging architecture, that automatically selects a segment having the analog value that is to be converted, may be utilized. This involves transformation of a reference segment to imitate a desired segment by multiplying the reference segment by a gain value and adding an offset value to the reference segment.
Although such a method improves the conversion rate substantially, an erroneous value of either the gain or offset or both may lead to incorrect digitization. For example, if an erroneous value of gain exists, a segment would be constructed to have a slope different from the desirable slope. This may result in an overlap band if the slope is higher than the desirable slope. An overlapped band would result in certain data points having more than one digital equivalent. If the slope is lesser than the desirable slope, this may result in a dead band. A dead band would result in certain data points not being digitized. Similarly, if an erroneous offset value exists, a segment would shift from the desirable location. This may result in both an overlap band and a dead band.
A method and system for calibrating a pipelined A/D conversion system for eliminating the effects of variance in gain and offset values, is therefore desirable.